Teams don’t make deep playoff runs without good offensive lines. It’s not just that good lines make it easier for coordinators to design a balanced attack. It’s that the extra quarterback protection often is the difference in a game.

Think about how often Matthew Stafford got flushed out of the pocket last season. Or had to step into a defense’s teeth because protection on the right side of the line collapsed.

Even if those plays didn’t result in sacks – the Lions tied for 11th in allowing the most – those quarterback pressures can be drive killers just the same. With Wagner, the Lions have the makings of its best offensive line in a generation.

Left tackle Taylor Decker and left guard Graham Glasgow were terrific as rookies last season. Travis Swanson is solid at center. Joe Dahl should be the right guard – Larry Worford signed with the Saints.

For years, Lions’ fans have decried the franchise’s inability to build a tough and nimble offensive line. When the Lions won, it was because of a handful of stars. Not because of the sort of meaty force that can grind in the middle of a football field.

Much has been made about Quinn’s time in New England. Whatever lessons he absorbed, the two most important were that organizations have to be ruthlessly efficient and that they have to protect the quarterback.

Matthew Stafford is not Tom Brady, obviously. But Brady isn’t Brady unless he has time to throw. Of all the characteristics that spring from that winning franchise, the most underrated is its talent in spotting and developing offensive linemen.

Wagner may not be a first-team All-Pro talent. And that’s fine. He doesn’t have to be. He just has to be an upgrade over Reiff.

Most NFL games are decided by a handful of plays. It’s easy to focus on the spectacular catch or interception. Sometimes, though, it’s about a holding penalty that stalls a promising drive in the second quarter. Or a stumble from the right tackle in the third, which leads to a rushed throw on 3rd-and-7, which leads to an incompletion and a punt.

So, yes, $9 million is double-take money for a right tackle. But that money isn’t necessarily about Wagner. It’s about the remaking of the most important unit on the football field, and how that can help Stafford take the next step in his development.

Mostly, though, it’s a signal from this franchise that the trenches are the key. Quinn showed last spring he and his staff have an eye for talent there with Decker and Glasgow.

No wonder, then, he let Reiff go. The former first-round pick didn’t develop to Quinn’s standards. He wasn’t good enough to keep up with the young talent emerging on the offensive line.

Just as Levy was no longer good enough to perform like he once did. Which is too bad, because he is an interesting and multi-layered human being who brought perspective to the game and to that locker room.

Traits, though, that don’t necessarily help win football games. Not like speedy – and healthy – linebackers and physical offensive lines.